The Institute of Engineering and Technology (IET) traces its heritage to 1871. Today its mission is to, “inspire, inform and influence the global engineering community, supporting technology innovation to meet the needs of society.” E&T (Engineering and Technology) is the IET’s award-winning monthly magazine and associated website for professional engineers.

E&T recently published an article by Holly Cave titled, “Charging ahead: the bid for better EV batteries.” The article’s premise is that, “The success of electric cars is ultimately defined by their batteries.” Organizations that contributed to the article include Argonne National Laboratory in Chicago, Daimler AG and Chevrolet. Enovix also contributed to the article regarding our work to solve the expansion problem associated with silicon anodes in conventional lithium-ion battery design and production—initially for wearable devices and eventually for EVs.

Specialist battery developer Enovix has created safer, more energy-dense Li-ion batteries for small electronic devices with a patented, porous silicon anode. The company says its batteries can be produced at high volume and low cost. Its platform includes 3D cell architecture, which increases energy density by eliminating dead space inside a conventional Li-ion battery to significantly improve its spatial efficiency.

The Enovix manufacturing process is also a novel one for batteries, adopting the photolithographic mask and etch techniques used to create solar cells. Combined, this approach delivers an energy density of 1.5 to 3 times that of conventional Li-ion batteries for wearable devices, depending on cell size and thickness. But could this battery be scaled up to the size needed for a car?

Enovix is optimistic. In-house projections promise a 16 per cent average annual increase in energy density, after commercialisation, for the foreseeable future, which is “over three times the historical 5 per cent annual increase from a conventional Li-ion battery,” according to the company’s senior marketing director, Bruce Pharr. While the initial focus is on batteries for small, wearable devices, the firm may eventually be able to produce batteries for cars, too. “As we extend beyond wearables into larger mobile markets, our production volume will increase, and our unit cost will decline,” he says. “The combination of higher energy density, improved safety and lower cost should eventually make Enovix an attractive choice for electric vehicles.”